Scroll fluid machine

ABSTRACT

A fixed scroll board  2  is attached to a casing  1 . Three fixed wraps  2   a  are provided on the fixed scroll board  2 . An eccentric bush  8  is rotatably supported by the casing  1 . A pivot shaft  12  is eccentrically supported in an eccentric hole of the eccentric bush  8 . A scroll board  3  with three orbiting wraps  3   a  is provided integrally with the pivot shaft  12 . A plurality of pumping chambers  13  are formed between the fixed wraps  2   a  and the orbiting wraps  3   a . An inlet port  4 , which is communicated with an intake chamber formed inside a seal wall  2   b  of the periphery of the fixed scroll board  2 , is provided. An outlet port  5  is provided on the fixed scroll board  2 . The pumping chambers  13  takes in and discharges working fluid three times during one rotation of the eccentric bush  8.

PRIORITY

This application claims priority to International application No. PCT/JP2008/063922 filed Jul. 28, 2008.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a scroll fluid machine used as a pump, etc. for example, to a scroll fluid machine used alone as a liquid pump for pressuring and transferring liquid refrigerant, oil, etc., or to a scroll fluid machine used as a pump in combination with an expander, an air compressor, a vacuum pump, a refrigerant gas compressor, an aerophose compressor, etc.

2. Description of the Related Art

In a conventional scroll fluid machine as shown in Japanese unexamined patent publication No. JP,08-210269,A (Aug. 20, 1996), the scroll fluid machine used as a pump includes a pump formed of a pair of a fixed scroll and an orbiting scroll, and thus there is the need to provide a self-rotation prevention mechanism such as a driven crank or an Oldham's ring.

Also, in a conventional scroll fluid machine as shown in Japanese patent No. JP,4014583,B (Jan. 21, 2007), a self-rotation prevention mechanism such as a driven crank or Oldham's ring is indispensable in a scroll fluid machine in which a pump and an expander are integrally formed. Further, to cool down a generator, a conventional scroll fluid machine is vertically arranged and liquid refrigerant flows from the upper side of the generator.

However, in the scroll fluid machine as described in Japanese unexamined patent publication No. JP,08-210269,A (Aug. 20, 1996), a self-rotation prevention mechanism preventing self rotation of the pivot shaft and the orbiting scroll is required to be provided, and thereby configuration becomes complicated, manufacturing costs are increased, and reliability is degraded. Also, intake and discharge can be conducted only one time during one rotation of a driving shaft, and thus pressure pulsation becomes large and vibration and noise are increased.

Also, in the scroll fluid machine described in Japanese patent No. JP,4014583,B (Jan. 21, 2007), a self-rotation prevention mechanism such as a driven crank mechanism is provided in addition to an expander part and a pump part. Thus the scroll fluid machine has complicated configuration, can be arranged only vertically, and thereby can not be arranged freely. Further, with only a single pumping chamber, pressure pulsation due to volumetric change occurs. Further, part of liquid refrigerant may be gasified due to heat of the generator, and thereby a pump may not perform its original function.

It is an object of the present invention to overcome the problems described above. That is, an object of the present invention is to provide a scroll fluid machine that is highly reliable with simple configuration.

SUMMARY OF THE INVENTION

To achieve this object, according to the present invention, a fixed scroll board is attached to a casing, a plurality of fixed wraps are provided on the above fixed scroll board, an orbiting scroll board is attached to an eccentrically-orbiting orbiting member, a plurality of orbiting wraps are provided on the above orbiting scroll board, and the above fixed wraps and the above orbiting wraps are configured to overlap each other.

Further, a seal wall is provided on the periphery of the above fixed scroll board, an intake chamber is formed between the above fixed scroll board and the above orbiting scroll board, and an inlet port, which is communicated with the above intake chamber, is provided on the above fixed scroll board.

Further, a cover is provided on the front side of the above fixed scroll board, an outlet port is provided in the center part of the above fixed wraps of the above fixed scroll board, and a collective outlet port, which is communicated with the above outlet port, is provided on the above cover.

Further, a plurality of the above fixed wraps and the above orbiting wraps may be provided at different arrangement angles such that phase angles of wraps adjoining each other are shifted.

Further, three of the above fixed wraps and the above orbiting wraps may be provided at

every 120° of arrangement angle such that the phase angles of the above fixed wraps adjoining each other are shifted by 120°.

Further, the above cover may be fixed to the above casing, and the above fixed scroll board may be attached to the above cover movably in the axial direction of the above orbiting member.

Further, the above orbiting member may be a pivot shaft rotatably supported in an eccentric hole of an eccentric bush.

Further, the above orbiting member may be a pivot shaft rotatably supported in an eccentric hole of a rotary shaft of an electric motor.

Further, three of the above orbiting wraps may be provided, and the inner center position of triangle formed of the centers of the above three orbiting wraps of the above orbiting scroll board, may be mounted to the above pivot shaft while preventing relative rotation.

Further, a fixed scroll may be attached to the above casing, an orbiting scroll is attached

to the end of the above pivot shaft opposite to the end to which the above orbiting scroll board is attached, and the wraps of the above fixed scroll and the wraps of the above orbiting scroll may be configured to overlap each other.

Further, a first scroll work part including the above fixed scroll board and the above orbiting scroll board may be used as a pump, while a second scroll work part including the above orbiting scroll and the above fixed scroll may be used as an expander.

Further, a heat-insulating board may be provided between the above first scroll work part and the above second scroll work part.

Further, the above collective outlet port of the above pump may be connected to an inlet of the above expander via an evaporator, and a relief valve connected to the above inlet port and the above collective outlet port may be provided.

Further, the above fixed scroll board may be made of cast iron, and the above orbiting scroll board is made of aluminum alloy.

Further, the above orbiting scroll board may be surface treated.

Further, the above fixed scroll board and the above orbiting scroll board may be made of aluminum alloy and at least either one of the above fixed scroll board and the above orbiting scroll board is surface treated.

Further, the above fixed scroll board and the above orbiting scroll board may be made of aluminum alloy and at least one of the surfaces of the above fixed scroll board and the above orbiting scroll board is coated with coating material.

Further, at least one of the above fixed scroll board and the above orbiting scroll board may be formed of self lubricating resin by molding.

Further, at least one of the above fixed scroll board and the above orbiting scroll board may be formed of self lubricating resin by molding, and at least one surface of the above fixed scroll board and the above orbiting scroll board may be coated with coating material.

Further, the above fixed scroll board may be formed by molding of self lubricating resin

that is the same or different than the above orbiting scroll board.

Further the above coating material may be diamond-like carbon, molybdenum disulfide or fluorine contained resin.

In the scroll fluid machine according to the present invention, a self-rotation prevention mechanism preventing self rotation of the orbiting member and the orbiting scroll board is not required, and thus configuration becomes simple, manufacturing costs are reduced and reliability is improved.

Further, when a plurality of the fixed wraps is provided and an adjoining fixed wrap is

phase shifted, pressure pulsation (pressure fluctuation) of the collective outlet port can be minimized and vibration and noise can be reduced.

Further, when a cover is fixed to the casing, the fixed scroll board is movably attached to the cover in the axial direction of the orbiting member, and the fixed member is configured to introduce fluid to its back face at outlet pressure, properly define the pressure receiving area and press the fixed member to the orbiting member with a slightly larger force than a fluid force on the pumping chamber side, sealing tightness of working fluid chambers provided between the fixed wraps and the orbiting wraps is increased, thereby leakage of working fluid is reduced and volumetric efficiency is improved.

Further, when the orbiting member is a pivot shaft rotatably supported in an eccentric hole of a rotary shaft of an electric motor, the electric motor and the pump can be integrally incorporated in an airtight container, and thereby no sealing is required even when inlet pressure of the pump is high, and thus configuration becomes simple and reliability is improved.

Further, when a generator is cooled down with working fluid after flowing from the expander, liquid refrigerant is not required to flow for the generator alone and can be directly taken in the pump part, and thus scroll fluid machine can be arranged freely being able to be installed either vertically or horizontally. Further, since heat of the generator is not transmitted to the liquid refrigerant, the liquid refrigerant is not gasified, and thus function of the pump is not inhibited.

Further the fixed scroll is attached to the casing on the opposite side of the fixed scroll

board, and the orbiting scroll is attached to the pivot shaft on the opposite side of the orbiting scroll board, and when the wraps of the fixed scroll and the wraps of the orbiting scroll overlap each other, a self-rotation prevention mechanism preventing self-rotation of the orbiting scroll is not required to be provided. Thus configuration of the scroll fluid machine becomes simple, and the reliability is improved.

Further, when the first scroll work part including the fixed scroll board and the orbiting scroll board is used as a pump and the second scroll work part including the orbiting scroll and the fixed scroll is used as an expander, the rotation rate of the pump and the expander are always the same, and thereby flow balance can be always maintained without a particular controller.

Further, when a heat-insulating board is provided between the first scroll work part and the second scroll work part, pumping function of the first scroll work part is not inhibited, and thus working fluid can be securely pressured and transferred.

Further, when the collective outlet port of the pump is connected to the inlet of the expander via an evaporator and a relief valve connected to the inlet port and the collective outlet port is provided, pressure of the working fluid at the collective outlet port can be prevented from increasing higher than a predetermined value, thereby working fluid flowing into the evaporator can be prevented from being overflowed, and thus working fluid can be prevented from flowing into the expander as liquid.

Further when the fixed scroll board is made of cast iron and the orbiting scroll board is made of aluminum alloy, slidability between the fixed scroll board and the orbiting scroll board is preferable.

Further, when surface treatment is applied to the orbiting scroll board, slidability between the fixed scroll board and the orbiting scroll board is further preferable.

Further, when the fixed scroll board and the orbiting scroll board are made of aluminum alloy, and surface treatment is applied to at least one of the fixed scroll board and the orbiting scroll board, slidability between the fixed scroll board and the orbiting scroll board is preferable.

Further, when the fixed scroll board and the orbiting scroll board are made of aluminum alloy, and at least one of surfaces of the fixed scroll board and the orbiting scroll board is coated with coating material, slidability between the fixed scroll board and the orbiting scroll board is preferable.

Further, when at least one of the fixed scroll board and the orbiting scroll board is formed of self lubricating resin by molding, slidability between the fixed scroll board and the orbiting scroll board is further preferable.

Further, when at least one of the fixed scroll board and the orbiting scroll board is made of self lubricating resin, and at least one of surfaces of the fixed scroll board and the orbiting scroll board is coated with coating material, slidability between the fixed scroll board and the orbiting scroll board is preferable.

Further, when the coating material is made of Diamond-Like Carbon, molybdenum disulfide or fluorine contained resin, slidability between the fixed scroll board and the orbiting scroll board is further preferable.

Further, when the above fixed scroll board is formed by molding of self lubricating resin that is the same or different from the above orbiting scroll board, slidability between the fixed scroll board and the orbiting scroll board is further preferable.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating a scroll fluid machine according to the present invention.

FIG. 2 is a view illustrating a fixed scroll board of the scroll fluid machine shown in FIG. 1.

FIG. 3 is a view illustrating an orbiting scroll board of the scroll fluid machine shown in FIG. 1.

FIG. 4 is a view illustrating a state in which fixed wraps and orbiting wraps of the scroll fluid machine shown in FIG. 1 overlap each other.

FIG. 5 is a view illustrating another scroll fluid machine according to the present invention.

FIG. 6 is a view illustrating another scroll fluid machine according to the present invention.

FIG. 7 is a view illustrating another scroll fluid machine according to the present invention.

FIG. 8 is a view illustrating another scroll fluid machine according to the present invention.

FIG. 9 is a view illustrating the Rankine cycle that a scroll fluid machine according to the present invention is applied.

FIG. 10 is a view illustrating another scroll fluid machine according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

FIG. 1 is a view illustrating a scroll fluid machine according to the present invention. FIG. 2 is a view illustrating a fixed scroll board of the scroll fluid machine shown in FIG. 1. FIG. 3 is a view illustrating an orbiting scroll board of the scroll fluid machine shown in FIG. 1. As shown in FIG. 1, a fixed scroll board 2 is attached to a casing 1, three fixed wraps 2 a are provided on the fixed scroll board 2, the adjoining fixed wraps 2 a are arranged at angular intervals of 120° while they are phase-shifted by 120° from each other. A seal wall 2 b is provided on the periphery of the fixed scroll board 2, and an inlet port 4 is provided on the fixed scroll board 2, and an outlet port 5 is provided at the center part of the fixed wraps 2 a of the fixed scroll board 2. Also, a rotary shaft 7 and an eccentric bush 8 are integrally formed, and the rotary shaft 7 and the eccentric bush 8 are rotatably supported by the casing 1 via a primary bearing 9 and a secondary bearing 10. A pivot shaft 12 (orbiting member) is rotatably supported in an eccentric hole of the eccentric bush 8 via a orbiting bearing 11, and a shaft seal 14 is provided between the casing 1 and the eccentric bush 8.

FIG. 4 is a view illustrating a state in which fixed wraps and orbiting wraps of the scroll fluid machine shown in FIG. 1 overlap each other. In the scroll fluid machine according to the present invention, an orbiting scroll board 3 is integrally attached to the pivot shaft 12. The three orbiting wraps 3 a are provided on the orbiting scroll board 3. As shown in FIG. 4, the fixed wraps 2 a and the orbiting wraps 3 a overlap each other and a plurality of pumping chambers 13 (working fluid chambers) are formed between the fixed wraps 2 a and the orbiting wraps 3 a. Also, the seal wall 2 b contacts with the orbiting scroll board 3, an intake chamber 4 a is formed between the fixed scroll board 2 and the orbiting scroll board 3, and the inlet port 4 is communicated with the intake chamber 4 a.

Also, as shown in FIG. 1, a cover 6 is provided on the front side of the fixed scroll board 2, and an outlet chamber 6 b communicated with the three outlet ports 5 is formed between the cover 6 and the fixed scroll board 2, and a collective outlet port 6 a communicated with the outlet chamber 6 b is provided on the cover 6. And, a first scroll work part including the fixed scroll board 2 and the orbiting scroll board 3 is used as a pump.

In this scroll fluid machine, the rotary shaft 7 is rotated by a motor, etc., the pivot shaft 12 and the orbiting scroll board 3 perform an eccentric orbiting motion around the center line of the body of the eccentric bush 8, and therefore the pumping chambers 13 formed between the fixed wraps 2 a and the orbiting wraps 3 a are gradually moved to inner periphery side. Accordingly, pressure transfer fluid (working fluid) such as liquid refrigerant or oil is injected into the inlet port 4, and is pressured and transferred in the pumping chambers 13, and is discharged from the outlet port 5, and then is discharged from the collective outlet port 6 a.

In the above scroll fluid machine, the three fixed wraps 2 a and the orbiting wraps 3 a overlap each other, and thereby the pivot shaft 12 and the orbiting scroll board 3 are not self-rotated, which will eliminate the need for a self-rotation prevention mechanism preventing self-rotation of the pivot shaft 12 and the orbiting scroll board 3. Therefore, the configuration of the scroll fluid machine becomes simple, the manufacturing costs are reduced, and the reliability is improved. Also, adjoining fixed wraps 2 a have 120° shifted phases, and thereby pressured transfer liquid is discharged in turn from each outlet port 5, which can decrease fluctuation of pressure in the outlet chamber 6 b and reduce vibration and noise. That is, the pump is made up of a plurality of scroll warps, which allows liquid refrigerant to be injected and discharged a plurality of times during one rotation of the eccentric bush 8. Thus the pressure pulsation, the vibration, and the noise of the pump can be reduced.

Although the phase of the fixed wraps 2 a is 120° shifted in the above embodiment, even a slight phase shift of the fixed wraps 2 a (for example 10° or less) can reduce pressure pulsation compared to no phase shift of the fixed wraps 2 a. Thereby vibration and noise of the scroll fluid machine can be reduced.

Second Embodiment

FIG. 5 is a view illustrating another scroll fluid machine according to the present invention. As shown in the drawing, the cover 6 is fixed to the casing 1, he fixed scroll board 2 is attached to the cover 6 movably in the axial direction of the pivot shaft 12. An outlet chamber seal 6 c is provided between the cover 6 and the fixed scroll board 2. A pin 15 is provided to prevent the fixed scroll board 2 from rotating with respect to the cover 6.

In this scroll fluid machine, similarly to the scroll fluid machine shown in FIG. 1, there is no need to provide a self-rotation prevention mechanism preventing self-rotation of the pivot shaft 12 and the orbiting scroll board 3, and thereby configuration becomes simple, manufacturing costs are reduced, and reliability is improved. Further, fixed scroll board 2 is pushed toward the right hand side of the paper in FIG. 5 due to pressure in the outlet chamber 6 b, thus the edge of the fixed wrap 2 a tightly contacts with the orbiting scroll board 3 and the edge of the orbiting wraps 3 a tightly contacts with the fixed scroll board 2, and thus sealing tightness of the pumping chambers 13 is increased, leakage of pressure transfer fluid is reduced and volumetric efficiency is improved.

Third Embodiment

FIG. 6 is a view illustrating another scroll fluid machine according to the present invention. As shown in the drawing, a stator 20 is fixed to the casing 1, a rotary shaft 24 is rotatably supported by the casing 1 via a first and second rotation bearings 22 a and 22 b, a rotor 21 is attached to the rotary shaft 24, and thus an electric motor is made up of the casing 1, the stator 20, the rotary shaft 24, rotor 21, etc.

Further, a pivot shaft (orbiting member) 25 is rotatably supported in an eccentric hole of the rotary shaft 24 via a first and a second eccentric bearing 23 a and 23 b while the center line of the rotary shaft 24 and the center line of the pivot shaft 25 are eccentrically positioned. That is, the pivot shaft 25 is rotatably supported eccentrically with respect to the rotary shaft 24. And, the inner center position of a triangle defined by the centers of the three orbiting wraps 3 a of the orbiting scroll board 3 is prevented from performing relative rotation and attached to the pivot shaft 25 with a bolt, etc.

In this scroll fluid machine, when a winding wire of the stator 20 is energized, the rotor 21 and the rotary shaft 24 rotate, and the pivot shaft 25 orbits around a center line of the rotary shaft 24, and thus similarly to the scroll fluid machine shown in FIG. 1, pumping chambers 13 formed between the fixed wraps 2 a and the orbiting wraps 3 a are gradually narrowed, and then pressure transfer fluid pressured and transferred is discharged from the collective outlet port 6 a.

In this scroll fluid machine, similarly to the scroll fluid machine shown in FIG. 1, there is no need to provide a self-rotation prevention mechanism preventing self-rotation of the pivot shaft 12 and the orbiting scroll board 3, and thereby configuration becomes simple, manufacturing costs are reduced and reliability is improved. Also, since an electric motor and a pump can be integrally incorporated in an airtight container, no sealing is necessary even when an intake pressure of a pump is high.

Fourth Embodiment

FIG. 7 is a view illustrating another scroll fluid machine according to the present invention. As shown in the drawing, an orbiting scroll board 3 is attached to a pivot shaft 25, and a key 26 is provided to prevent the orbiting scroll board 3 from rotating with respect to the pivot shaft 25. A fixed scroll 30 is attached to the casing 1, an inlet port 32 is provided on the fixed scroll 30, an orbiting scroll 31 is attached to the end of the pivot shaft 25 opposite to the end to which the orbiting scroll board 3 is attached, wraps of the fixed scroll 30 and wraps of the orbiting scroll 31 overlap each other, a plurality of expansion chambers 33 are provided between the wraps of the fixed scroll 30 and the wraps of the orbiting scroll 31, the inlet port 32 is communicated with the expansion chamber 33 in the center part, the expansion chamber 33 in the periphery part is communicated with inside the casing 1, and a discharge port 34 is provided on the casing 1. And, a generator is made up of the casing 1, a stator 20, a rotary shaft 24, a rotor 21, etc. A first scroll work part including the fixed scroll board 2 and the orbiting scroll board 3 constitutes a pump. Further, a second scroll work part including the fixed scroll 30 and the orbiting scroll 31 constitutes an expander. Further, this scroll fluid machine constitutes a Pump Expander including a pump, an expander and a generator.

In this scroll fluid machine, when a high-pressure working fluid is injected into the inlet port 32, working fluid is expanded in the expansion chamber 33, and thereby the orbiting scroll 31 and the pivot shaft 25 orbit eccentrically around the center line of the rotary shaft 24, and thereby the rotary shaft and the rotor 21 rotate. Therefore, an electric power is generated in a coil of the stator 20. Expanded working fluid is discharged from the discharge port 34. Meanwhile, when the rotary shaft 24 rotates, pumping chambers 13 formed between the fixed wrap 2 a and the orbiting wrap 3 a are gradually narrowed, and thereby pressured and transferred working fluid is discharged from the collective outlet port 6 a.

In this scroll fluid machine, pressured and transferred working fluid is three times injected and discharged during one rotation of the rotary shaft of a pump, and thus pressure pulsation is significantly reduced while vibration and noise are decreased. Further, similarly to the scroll fluid machine shown in FIG. 1, there is no need to provide a self-rotation prevention mechanism preventing self-rotation of the orbiting scroll board 3, and there is no need to provide a self-rotation prevention mechanism preventing self-rotation of the orbiting scroll 31 of the expander as well, and thereby configuration becomes simple, manufacturing costs are reduced, and reliability is improved. Also, rotation rates of the pump and the expander are always the same, and thus as the expander runs at high speed, so does the pump, and therefore flow balance can be constantly maintained without the need of a particular controller.

Fifth Embodiment

FIG. 8 is a view illustrating another scroll fluid machine according to the present invention. As shown in the drawing, this scroll fluid machine, similarly to the scroll fluid machine shown in FIG. 7, constitutes a Pump Expander including a pump, an expander and a generator. Further, similarly to the scroll fluid machine shown in FIG. 5, the fixed scroll board 2 is attached to the cover 6 movably in the axial direction of the pivot shaft 25, and the outlet chamber seal 6 c is provided between the cover 6 and the fixed scroll board 2, and the pin 15 is provided to prevent the fixed scroll board 2 from rotating with respect to the cover 6.

In this scroll fluid machine, similarly to the scroll fluid machine shown in FIG. 7, there is no need to provide a self-rotation prevention mechanism preventing self-rotation of the orbiting scroll board 3 and there is no need to provide a self-rotation prevention mechanism preventing self-rotation of the orbiting scroll 31 of the expander, thereby configuration becomes simple, manufacturing costs are reduced, and reliability is improved. Further, as the expander runs at high speed, so does the pump, and therefore flow balance can be constantly maintained without the need of a particular controller. Further, similarly to the scroll fluid machine shown in FIG. 5, sealing tightness of the pumping chambers 13 is increased, leakage of working fluid is reduced and volumetric efficiency is improved.

Sixth Embodiment

FIG. 9 is a view illustrating the Rankine cycle of a scroll fluid machine according to the present invention. As shown in the drawing, the pump expander 60 as the scroll fluid machine shown in FIGS. 7 and 8 includes a pump 50, an expander 51, and a generator 52. Further, a collective outlet port 6 a of the pump 50 is connected to the inlet port 32 of the expander 51 via an evaporator 56. And, the discharge port 34 of the expander 51 is connected to an inlet port 4 of the pump 50 via a condenser 53. Further, a relief valve 57 is provided connected to the inlet port 4 and the collective outlet port 6 a. Further, a boiler 55 is connected to the evaporator 56 and a cooler 54 is connected to the condenser 53. Further, an incoming panel 58 is connected to the generator 52.

In this Rankine cycle, working fluid such as chlorofluorocarbon (Freon) discharged from the discharge port 34 of the expander 51 flows in the condenser 53, and temperature of the working fluid is decreased by water circulating through the condenser 53 and the cooler 54, and the working fluid is liquefied and flows into the inlet port 4 of the pump 50. Next, the liquefied working fluid is pressured by the pump 50 and the pressure becomes high, thus it flows into the evaporator 56 from the collective outlet port 6 a. The working fluid is heated and becomes high-pressure gas at the evaporator 56, by water heated at the boiler 55. This high-pressure working fluid flows into the inlet port 32 of the expander 51. Thereby the rotary shaft rotates, and the generator 52 generates and transmits the electric power to the incoming panel 58. And, the working fluid discharged from the discharge port 34 of the expander 51 flows into the condenser 53 and is liquefied. Further, the relief valve 57 is provided connected to the inlet port 4 and the collective outlet port 6 a, and thus when the pressure of working fluid at the collective outlet port 6 a is increased to a certain level or higher, the working fluid flows into the inlet port 4 via the relief valve 57.

In this Rankine cycle, since the pump 50, the expander 51, and the generator 52 are integrally formed, the number of parts is reduced and it can be formed compact, which enables the whole Rankine cycle to be formed simple, compact and lightweight, and therefore maintenance becomes easy compared to the case in which the pump and the expander are separately installed. Further, since the pump 50 is formed integrally with the expander 51 and the generator 52, the pump 50 is directly driven by the expander 51 and thus does not consume the electric power generated by the generator 52. Therefore the loss of power generation of the Pump Expander 60 is reduced, and the efficiency of power generation is increased. Also, when pressure of working fluid at the collective outlet port 6 a exceeds or equals to a certain level, the working fluid flows into the inlet port 4 via the relief valve 57, thus pressure of working fluid at the collective outlet port 6 a can be prevented from increasing to a certain level, and thus amount of the working fluid flowing into the evaporator 56 can be prevented from excessively increasing, and thereby working fluid can be prevented from flowing into the expander 51 as liquid due to lack of evaporation capacity of the evaporator 56.

Seventh Embodiment

FIG. 10 is a view illustrating another scroll fluid machine according to the present invention. As shown in the drawing, this scroll fluid machine, similarly to the scroll fluid machine shown in FIG. 7, constitutes a pump expander including a pump, an expander and a generator. Further, similarly to the scroll fluid machine shown in FIG. 5, the fixed scroll board 2 is attached to the cover 6, movably in the axial direction of the pivot shaft 25, the outlet chamber seal 6 c is provided between the cover 6 and the fixed scroll board 2, and the pin 15 is provided to prevent the fixed scroll board 2 from rotating with respect to the cover 6. Further, the heat-insulating board 41 formed of material with low thermal conductivity such as fluororesin is provided between a first scroll work part and a second scroll work part. That is, the periphery of the heat-insulating board 41 is sandwiched between the casing 1 and the cover 6, a hole is formed in the center part of the heat-insulating board 41 and a projection of the orbiting scroll board 3 projecting toward the pivot shaft 25 passes through the hole, and intermediate portion of the heat-insulating board 41 between the periphery and the center part is located between the orbiting scroll board 3 and the end of the rotary shaft 24 on the side of the orbiting scroll board 3. That is, the heat-insulating board 41 is provided between the pump and the generator.

In this scroll fluid machine, similarly to the scroll fluid machine shown in FIG. 7, there is no need to provide a self-rotation prevention mechanism preventing self-rotation of the orbiting scroll board 3 and there is no need to provide a self-rotation prevention mechanism preventing self-rotation of the orbiting scroll 31 of the expander as well, thereby configuration becomes simple, manufacturing costs are reduced, and reliability is improved. Also, as the expander runs at high speed, so does the pump, and therefore flow balance can be constantly maintained without the need of a particular controller. Further, similarly to the scroll fluid machine shown in FIG. 5, sealing tightness of the pumping chambers 13 is increased, leakage of working fluid is reduced and volumetric efficiency is improved. Further, even if a generator and an expander are highly heated, the heat-insulating board 41 can prevent heat of the generator and the expander from being transmitted to the pump. That is, the heat-insulating board 41 can prevent thermal conduction from the casing 1 to the cover 6 while the heat-insulating board 41 can prevent convection flow from space of the generator side to space of the pump side. Accordingly, working fluid (liquid refrigerant) injected in a pump can be prevented from being heated by a generator and an expander, and thus working fluid can be prevented from being gasified. Therefore, no air bubble is mixed with working fluid in the pump. Accordingly, the first scroll work part, i.e. the pump can securely pressure and transfer the working fluid since its pumping function is not inhibited.

Alternatively, the heat-insulating board may be provided between the generator and the second scroll work part, i.e., the expander. Also, in this case, even if the expander is highly heated, the heat-insulating board can prevent heat of the expander from being transmitted to the pump and thus working fluid can be prevented from being gasified. Therefore, no air bubble is mixed with working fluid in the pump. As such, the first scroll work part, i.e. the pump can securely pressure and transfer the working fluid since its pumping function is not inhibited.

OTHER EMBODIMENTS

Alternatively, the fixed scroll board 2 may be formed of cast iron while the orbiting scroll board 3 may be formed of aluminum alloy. In this case, slidability between the fixed scroll board 2 and the orbiting scroll board 3 is preferable.

Also, surface treatment such as anode oxidation may be applied to the orbiting scroll board 3 formed of aluminum alloy. In this case, slidability between the fixed scroll board 2 and the orbiting scrolls board 3 is further preferable.

Alternatively, the fixed scroll board 2 and the orbiting scroll board 3 are formed of aluminum alloy, and surface treatment such as anode oxidation, etc. may be applied to at least one of the fixed scroll board 2 and the orbiting scroll board 3. In this case, slidability between the fixed scroll board 2 and the orbiting scrolls board 3 is preferable.

Alternatively, the fixed scroll board 2 and the orbiting scroll board 3 are formed of aluminum alloy, and at least one surface of the fixed scroll board 2 and the orbiting scroll board may be coated with coating material such as diamond-like carbon (DLC), molybdenum disulfide, fluorine contained resin, etc. In this case, slidability between the fixed scroll board 2 and the orbiting scrolls board 3 is preferable.

Alternatively, the orbiting scroll board 3 may be formed of self lubricating resin by molding. In this case, the fixed scroll board 2 may be formed by molding of the self lubricating resin that is the same as or different from the orbiting scroll board 3. In these cases, slidability between the fixed scroll board 2 and the orbiting scrolls board 3 is preferable.

Alternatively, the fixed scroll board 2 or the orbiting scroll board 3 is formed of self lubricating resin, and at least one surface of the fixed scroll board 2 and the orbiting scroll board 3 may be coated with coating material such as diamond-like carbon, molybdenum disulfide, fluorine contained resin, etc. Also, in this case, slidability between the fixed scroll board 2 and the orbiting scrolls board 3 is preferable.

The present invention is not limited to the above embodiments and may be combined with any of above embodiments.

Although three of the fixed wraps 2 a and the orbiting wraps 3 a are provided in the above embodiments, a plurality of the fixed wraps and the orbiting wraps may be provided respectively. 

1. A scroll fluid machine, wherein: a fixed scroll board is attached to a casing; a plurality of fixed wraps are provided on the fixed scroll board; an orbiting scroll board is attached to an eccentrically-orbiting member; a plurality of orbiting wraps are provided on the orbiting scroll board; and the fixed wraps and the orbiting wraps are configured to overlap each other.
 2. The scroll fluid machine according to claim 1, wherein: a seal wall is provided on the periphery of the fixed scroll board; an intake chamber is formed between the fixed scroll board and the orbiting scroll board; and an inlet port, which is communicated with the intake chamber, is provided on the fixed scroll board.
 3. The scroll fluid machine according to claim 1, wherein: a cover is provided on the front side of the fixed scroll board; an outlet port is provided in the center part of the fixed wraps of the fixed scroll board; and a collective outlet port, which is communicated with the outlet port, is provided on the cover.
 4. The scroll fluid machine according to anyone of claims 1, wherein a plurality of the fixed wraps and the orbiting wraps are provided at different arrangement angles such that phase angles of the fixed wraps and the orbiting wraps adjoining each other are shifted.
 5. The scroll fluid machine according to anyone of claims 1, wherein three of the fixed wraps and the orbiting wraps are provided at every 120° of arrangement angle such that the phase angles of said fixed wraps and said orbiting wraps adjoining each other are shifted by 120°.
 6. The scroll fluid machine according to anyone of claims 1, wherein: the cover is fixed to the casing; and the fixed scroll board is attached to the cover movably in the axial direction of the orbiting member.
 7. The scroll fluid machine according to anyone of claims 1, wherein the orbiting member is a pivot shaft rotatably supported in an eccentric hole of an eccentric bush.
 8. The scroll fluid machine according to anyone of claims 1, wherein the orbiting member is a pivot shaft rotatably supported in an eccentric hole of a rotary shaft of an electric motor.
 9. The scroll fluid machine according to claims 8, wherein: three of the orbiting wraps are provided; and the inner center position of a triangle formed of the centers of the three orbiting wraps of the orbiting scroll board, is attached to the pivot shaft while preventing the relative rotation.
 10. The scroll fluid machine according to claim 8, wherein: a fixed scroll is attached to the casing; an orbiting scroll is attached to the end of the pivot shaft opposite to the end to which the orbiting scroll board is attached; and the wraps of the fixed scroll and the wraps of the orbiting scroll are configured to overlap each other.
 11. The scroll fluid machine according to claim 10, wherein a first scroll work part including the fixed scroll board and the orbiting scroll board is used as a pump, while a second scroll work part including the orbiting scroll and the fixed scroll is used as an expander.
 12. The scroll fluid machine according to claim 11, wherein a heat-insulating board is provided between the first scroll work part and the second scroll work part.
 13. The scroll fluid machine according to claim 11, wherein: the collective outlet port of the pump is connected to an inlet of the expander via an evaporator; and a relief valve connected to the inlet port and the collective outlet port is provided.
 14. The scroll fluid machine according to anyone of claims 1, wherein: the fixed scroll board is made of cast iron; and the orbiting scroll board is made of aluminum alloy. 15-16. (canceled)
 17. The scroll fluid machine according to anyone of claims 1, wherein: the fixed scroll board and the orbiting scroll board are made of aluminum alloy; and at least one of the surfaces of the fixed scroll board and the orbiting scroll board is coated with coating material.
 18. The scroll fluid machine according to anyone of claims 1, wherein at least one of the fixed scroll board and the orbiting scroll board is formed of self lubricating resin by molding. 19-20. (canceled)
 21. The scroll fluid machine according to claim 15, wherein the coating material is diamond-like carbon, molybdenum disulfide or fluorine contained resin. 